However, the standard model for air-conditioned seats, developed by scientists at the Department of Energy's National Renewable Energy Laboratory (NREL), works like this: The fabric of the car seat is a porous mesh, so air can flow through it.
As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs.
The medical term for difficulty swallowing is Dysphagia. Aspiration is the medical term for inhaling small particles of food or drops of liquid into the lungs. Aspiration may occur without anyone knowing if the amount of food or liquid is small (Silent Aspiration). The first sign ofaspiration may be trouble breathing or signs of pneumonia.